A former FBI agent accused of orchestrating the 1982 slaying of a gambling executive called organized crime members to set the killing in motion, a former Boston mobster testified Tuesday.

Stephen “The Rifleman” Flemmi, testifying at the murder trial of FBI agent John Connolly, said plans for the murder of former World Jai-Alai president John Callahan began after the mob got a phone call from Connolly.

Agents wanted to question Callahan about another murder orchestrated by the mob and believed he would cooperate, Flemmi said he was told. Boston’s Winter Hill Gang believed Callahan needed to be killed to ensure his silence, Flemmi said.

Connolly, 68, is accused of helping orchestrate Callahan’s death. He is already serving a 10-year federal prison sentence on racketeering and other charges but faces life in prison if convicted in the current case. Mobsters paid Connolly roughly $235,000 over the years for information and protection, Flemmi testified Monday.

Flemmi is serving life in prison after pleading guilty to his role in the Callahan slaying and other killings. Flemmi told the jury that another member of the Winter Hill Gang, James “Whitey” Bulger, got the tip from Connolly and then told him. Bulger and Flemmi then met with a mob hitman in a New York hotel and set up Callahan’s death in Florida, Flemmi said, adding that they wanted the murder to happen far from Boston.

“We didn’t want any heat on ourselves,” Flemmi said.

Callahan was later found dead in the trunk of his Cadillac at Miami International Airport. Bulger, 79, remains a fugitive on the FBI’s “Ten Most Wanted” list.

During cross-examination later Tuesday Connolly’s attorney Manuel Casabielle argued that Flemmi had lied in the past under oath and was mad at his client.

“That was then, it’s different now,” Flemmi said when asked about his past misstatements. “Now I’m cooperating with the government. I’m telling the truth.”

Flemmi blamed Connolly for past lies.

“I expected the FBI to come to my defense and support me, and John Connolly assured me that that would happen. That’s the reason why I wasn’t candid,” Flemmi said during questioning that was often contentious.

“You have a habit of taking things out of context,” Flemmi told Casabielle at one point.

Casabielle asked if Flemmi ever told Connolly directly that he killed anyone. Connolly answered “no” but that it was “obvious from the information he gave us that people were killed.”

“You give us information on one person and that person gets killed. Then he gives us information on a second person, and that person gets killed. Then he gives us information on a third person and that person gets killed,” Flemmi said. “I mean, he’s an FBI, he’s not a stupid person.”

Page 2 of 2 - Flemmi’s testimony Tuesday also included references to killings Flemmi took part in or cleaned up, and a stash of guns he kept at his mother’s house: including submachine guns with silencers, sawed off shotguns and high-powered rifles.

Casabielle was expected to continue his cross-examination of Flemmi on Wednesday.